The gene-induction and repression basis for mitochondrial participation in ovarian follicular maturation and luteinization continue to be the long-term objectives of this study. Specific aims of the project are directed at determining how ovarian mitochondria are regulated by long-term actions of steroidogenic hormones. Effects of the gonadotropins FSH and LH, and estradiol on ovarian cells as follicles mature and differentiate to corpora lutea will be studied. Particularly, altered gene expression in mitochondria will be examined to determine the role specific mitochondrial genes play in providing mitochondrial enzyme apparatus for steroid synthesis. Specifically, the study will compare RNA transcripts synthesized from mitochondrial genes as they are initiated, produced and processed in follicular and luteal cells, as well as in follicles incubated with individual or combinations of steroidogenic hormones. Granulosa and theca cell mitochondria will also be studied to clarify their roles in follicular maturation related to these gene expression changes. DNA promoters which are regulated to produced the differences in expression already observed will be identified. Altered specificity of RNA processing during luteinization will also be examined. Basic knowledge obtained from these studies are valuable health sciences including molecular endocrinology, gyneocology, reproduction and fertility regulation, and oncology. Furthering our understanding of normal gonadotropin and steroid regulation of ovarian functioning, and the mechanism by which cellular organelles respond to reproductive hormone stimulation, is important in understanding dysfunction of this system in its varied manifestations, and in controlling both normal function and dysfunction. Methodologies to be used includes in vitro incubation of follicles, labeling and isolation of mitochondrial RNA transcripts, restriction nuclease mapping of porcine mitochondrial DNA, agarose gel electrophoresis, northern and southern transfers and hybidization.